The PAX 3 Screen (3-pack) is an Original Equipment Manufacturer (OEM) product, meaning it is manufactured by Pax Labs and to their high standards. These screens work to avoid build-up in your PAX 3 oven. Since they serve as a filter for your vaporizer, they need to be changed regularly (after every 25 uses). Cleaning the screens is quick and easy, just place them in a pot of boiling water and wipe them dry. Cleaning your screens will remove the build-up and give them longer life. These screens are also compatible with the PAX 2 vaporizer.